Dental flask



No. 620,303. Patented Feb. 28, I899. F. GBOSHANS;

DENTAL FLASK.

(Application filed Dec. 10, 1898.)

(No Model.)

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UNITED STATES PATENT OFFICE.

FERDINAND GROSHANS, OF BALTIMORE, MARYLAND.

DENTAL FLAS K.

SPECIFICATION forming part of Letters Patent No. 620,303, dated February28, 1899.

Application filed December 1898. Serial No. 698,803. (No model.)

To all whom it may concern.-

Be it known that I, FERDINAND GROSHANS,

, a citizen of the United States, residing at Baltimore, in the State ofMaryland, have invented certain new and useful Improvements in DentalFlasks, of which the following is a specification.

My invention relates to improvements in vulcanizing-flasks such as areused in mechanical dentistry; and the invention consists of an improvedoontruction of the parts whereby certain advantages, which will bepointed out, are derived.

The invention is illustrated in the accompanying drawings.

Figure 1 is a cross-section view of the flask with the parts boltedtogether Fig. 2 is a top plan View of the cover of the flask and showsthe projecting recessed flanges which receive the bolts and washers, onewasher only being in position. Fig. 3 is a top plan View of the upperhalf of the flask with the cover removed and shows the reduced openingin the top. Fig. 4 is an inside plan view of the lower half of theflask, and Fig. 5 illustrat-es a side view of the flask and shows theparts all looked together by the bolts.

Referring now by letters to the drawings, A designates the lower half.of the flask, B the upper half, and- O the cover. The lower half A ofthe flask has inside sloping walls, which are rounded at d, where theside wall merges into the bottom of the flask, the object of this shapebeing to aid in thewithdrawal of the plaster cast. This half of theflask at its top rim edge e is provided with downwardly-projectinghook-shaped lugs f, two of which are located together to form a pair oneach side of the flask. The head of a bolt, hereinafter described,engages with each pair of these lugs. The lower half A has in its bottoman opening and aremovable plate a of shape corresponding with theopening within said lower half and closing the opening, said removableplate being provided with retaining-lugs a, which lap over onto thebottom. When the plaster cast is to be removed from the lower half A, ahammer may be tapped onto the lower side of said plate a.

Heretofore in removing the plaster cast from flasks considerable troublehas been experienced in freeing the plaster cast from the flask, and ithas been commonly necessary to strike with a hammer on the edges of theflask in order to loosen the plaster cast. Such hammering is injuriousto the flask and battersthe edges to the extent that a tight joint withthe other half of the flask cannot be made when the two halves arelocked together. In order to overcome this objection, each half of theflask is provided with one or more projecting knocker-lugs g, located onthe sides, and it has been found that the plaster cast can be easilyremoved by hammering on these lugs, thereby avoiding injury to theflask.

An upward-projecting lug h is on opposite sides of the lower half of theflask and immediately adjoins one pair of lugs f, the purpose of whichwill be hereinafter set forth.

The upper half B of the flask conforms in shape to the lower half andfits snugly thereon, making a practically tight joint. This half isprovided on its bottom edge c with pairs of projectinglugs f. These lugsf are so located that when the two flask parts are placed together thepairs of lugs f on the lower half will register with the pair of lugs fon the upper half and the bolt has position in both pairs of lugs.

The upper half of the flask is provided with guide-lugs h,separated fromthe pairs" of lugs f by a space i, into'which the lug h on the lowerflask part takes when the two halves are secured together. It will beseen that the upward-projecting lug h on the part A and the guide-lugs hon the part B will serve to so look the two parts as to prevent themfrom having lateral play. I

The upper half of the flask is rounded and curved inward at d and formsa partial top with an opening j, through which the plasterof-paris' in asemiliquid or plastic state is poured into the flask. This rounded andinward-curved portion d or the inner side of the flask has the samefunctionas the rounded portion cl on the lower half-to wit, enables theplaster cast to be more readily freed from the flask; but the partialtop thus formed serves to confine and stay the teeth-mold in positionwhen inserting the flask with plaster.

The cover 0 is formed with a concavo-con-- vex rim edge is, which lapsand fits snugly over the inward-curved partial top of the upper half.The cover is also provided at each side with projecting recessed flangesZ, which a are slightly upwardly inclined. These flanges are provided ontop with a circular recessed or sunken face 'm, which forms a seat for around washer n, and each of said flanges has a slot or cut-away portion0 for the bolt to enter sidewise.

A bolt 19, having at one end a T-head and at the other end a nut q andthe washer n, secures the two flask parts and cover together. The T-headof the bolt 19 is first placed under the hook-lugs f on the lower halfof the flask, the bolt carrying the washer n and nut is then swung intothe slot or cut-away portion 0 of the projecting flanges 7c, and theWasher is permitted to seat into the circular recess m.

As the flanges l are upwardly inclined and are provided with therecessed face, it Will be seen that the bolts will not accidentally fallout before the nuts q have been tightened on them. Another advantage ofthe upwardlyinclined flanges l is that straight bolts may be used tosecure the parts together, whereas in many dental flasks the bolts haveto be bent to fit the outside curvature of the flask.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is

1. In a dental flask the combination of a three-part fiaskthe lowerpart, A, at the juncture of the inside wall and bottom provided with arounded portion, cl; the upper part, B, having its side wall at the toprounded and curved inward and forming a partial top having an opening,j; a cover, 0, having a concave bottom face, which laps over the saidinward-curved partial top, and means to clamp the three flask partstogether, substantially as described.

2. In a dental flask the combination'of a three-partfiaskthe lower part,A, at the juncture of the inside and bottom walls provided with arounded portion, d; the upper part, B, havingits side wall at the toprounded and curved inward and provided with a top opening; knocker-lugson the sides of the said upper and lower parts; a cover which takes overthe top of the inward-curved side walls, and means on the cover and thelower part, A, to clamp the three parts together.

3. In a dental flask the combination of a three-part flaskthe lowerpart, A, provided with downward-projecting hook-lugs, f, in pairs; theupper part, B, having its side walls at the top rounded and curvedinward and forming a partial top with an opening, j; a cover, C,provided with upwardly-inclined projecting flanges having on top acircular recess, m, and a side slot, 0; a bolt one end of which takesunder the hook-lugs on the lower part of the flask and the other endoccupies the slot in said flanges and has a washer which fits in thesaid recess on the flanges and a nut on the bolt, substantially asdescribed.

4. In a dental flask the combination of a lower part, A, provided at thejuncture of the inside and bottom walls with a rounded portion, (1; aremovable plate, a, fitting in an opening in the bottom of said lowerpart; an upper part, B; and means to clamp the lower and the upper partstogether.

In testimony whereof I affix my signature in the presence of twowitnesses.

FERDINAND eRosnANs.

Witnesses CHARLES B. MANN, J r., Gno. Kon'rnnn.

